Hand and air low pressure grease gun



Nov. 23, 1937. A. JOHNSON 2,099,959

HAND AND AIR LOW PRESSURE GREASE GUN Filed April 21, 1934 R 5 n g a C@,W n w Q n gt un e@ W no n Q 3 x 2J YN e n n Q Q gn m i Q n m E N E 9%9% I j i 1 3% I a i t w i s l I 3mm/W0@ Joum/ Q 9 a @www Patented Nov.23, 1937 August Johnson, Fargo, N. Dak., assigner to Jiify LubricatorCompany, Inc., Fargo, N.` Dak., a corporation of North DakotaApplication April 21, 1934, Serial No. 721,806

9 Claims.

This invention relates to a loW air pressure hand greasegun of unitarynature so that it can be easily handled and carried from place to placefor greasing purposes.

A feature resides in a low pressure grease gun which is self-containedand which is adapted to carry a volume of air in one end and grease inthe other end. This gun is of a simple nature and is constructed so thatthe operator may lreadily apply it to a bearing which is to be greased.'Ihe application of the nozzle end to the bearing to be greasedautomatically releases the nozzle sothat the air in the reservoirchamber of the gun Will force the grease into the bearin 151 under lo-wpressure.

It is also a feature to provide a discharge nozzle Which automaticallycloses `when thegun is not in use and opens when in use. The nozzle isprovided With a check valve means which 2b holds the grease against backpressurefin the discharge nozzle and permits the operator to exertv anyadditional force that is desirable in injecting .the grease into thebearing from the nozzle by bearing against the rear of the gun. Z8: Thenozzle is slidable so that its inner end may act as a plunger inelecting the grease in the discharge end of the nozzle proper. `Thenozzle is of a simple construction and is formed so thattheloperatingfparts thereof may be disassembled il@ or replaced at anytime.

My low pressure grease gun is provided with a floating piston assemblywherein a double acting piston is provided, oneside of which takes theair pressure, the other side of which acts against 351 the grease in thelubricant compartment. 'I'his iloating piston assembly includes a pairof bearing members which guide the floating piston assembly in thecylinder of the. gun. Thus I pro` vide a piston assembly which is freeto operate 4G and will not jam but ow freely in the gun cylinder. Thisis important in the free operation of my grease gun.

l The cylinder is provided with retainer` ring means which limit themovement of the piston in the'cylinder and act as stops. The rear end ofmy low pressure grease gun is formed with a removable cap under which anair valve is provided and the valve is formed with an air release 50 capso that the air chamber may be relieved when it is desired to fillgrease into the cylinder of the gun, thus making a unitary air valve andrelease which; is simple to operate.

`rIn the drawing I have illustrated my low air 55; pressure' hand greasegun, and:

(o1. zal-47.4)

Figure 1 is a longitudinal section of my low air pressure hand greasegun in its assembly.

Figure 2 is an enlarged section detail of the nozzle and a portion ofthe gun cylinder.

My low air pressure hand grease gun A is pro- 5 vided With a tubularcylinder I which is closed at one end by the wall I I. An air valve I2is mounted in the Wall II and is provided with an air release cap I3.The cap I3 is constructed so as to release the air from the air chamberI4 l0 when the cap I3 is in one position, and to close the valve I 2when in another position. The valve I2 is provided with an automaticclosing valve Within the same of ordinarily Well known constructure. Thegun A is provided with a closure .l5Y

cap I5 which incloses the valve I2 and provides a bearing for theoperators hand in using the grease gun A. 'I'he gun A is designed to beoperated by hand and carries air pressure in the chamber I4. A gun ofthis character is termed a low pressure greasing device and it isadapted to be used without any `air hose connecting the same so that thegun is of a unitary self-contained nature with the desired pressure ofair carried in the chamber I4 which is adapted to press against 25 thegrease in the chamber I6.

`I provide a` I loating piston assembly B which includes oppositelydisposed leather cups I'I and I8 betweenwhich a Washer bearing I8 ismounted. The cups I'I and I8 are held assembled together by the washers20 and 2| which t inside of the leather cups I1 and I 8 and are held inplace by the bearing cup-shaped flanged washers 22 and 23 and the bolt24 which extends through the same. The lloating piston assembly Boperates in the cylinder I0. It is desirable that the piston assembly Bfloat freely in the cylinder I0 and yet it must be of a simple structuredesigned so that it will not get out of order and to insure itsfreeloperation at all times. I accomplish this by means of thecup-shaped anged Washers 22 and 23 Which are clamped in place by thebolt 24 and which have bearing flange rings 25 which freely engage theinner Wall of the cylinder I0 so as to act as guides on either side ofthe floating piston assembly B. Thus the oating piston B cannot cock toone side or get out of line in operation, but is guided to slide freelyby the inuence of the air in the chamber I4 to force the grease out ofthe chamber I6. The movement oi the piston in the cylinder I0 isregulated by the spring stop rings 26 and 21 which are positionedadjacent the respective ends of the cylinder I0. The ring 2B is spacedsufliciently from the wall II so that the grease chamber I6 cannot befilled with too 55 zle C is formed within the tapered passageway..v 30with an increased wall in which the collar 3| is threaded so that it maybe removed." The edge of the collar forms a valve seat 32 for the ballcheck valve 33. The ball valve 33 is adapted to be guided onlongitudinally-extending ribs 34 which hold the ball freely slidabletoward and away from the seat 32. An annular shoulder 35 limits theforward movement of the ball 33 on the ribs 34. Thus the ribs provideameans of centrally guiding the ball in the nozzle C. Slots 36 betweenthe ribs 34 and extending through the annular ring shoulder 35 permitthe grease to pass through the passageway 39 of the nozzle and throughthe opening 3'I in the collar 3l, past the ball 33 and through the slots36 into the front chamber 36 of the nozzle. The nozzle assembly C isprovided with a slidable pressure release tip 33 which has a tapereddischarge end adapted to t into the opening or tting which is to begreased when the gun A is in operation to inject grease into a bearing.The tip 38 is threaded at 49 to the hollow plunger 4l which is guided bythe collar 42 formed in the wall of the nozzle C. The inner end of theplunger 4I is provided with a leather washer valve 43 held inthe end ofthe plunger by the screw 44 so that the washer/may be replaced when itis desired. Holes 45 connect the chamber 30' with the inner passage 46extending through the plunger 4I and connecting with the passage 4'Ithrough the tip 38. A coil spring 48 normally holds the plunger'inposition with the valve 43 against the shoulder 49 of the collar 42 toclose the nozzle C when the tip 38 is in the position illustrated inFigure 1.

In operation the grease gun A is filled with grease in the chamber I6and by means of the valve I3 the chamber I4 is filled with compressedair which forces the floating piston assembly B against the grease inthe chamber I6. This packs the grease into the nozzle C, opening thecheck valve 33 and dlling the chamber 30 with grease. The pressure ofthe grease against the washer Valve 43 and the head of the screwv 44assists in keeping the plunger 4I in closed position as illustrated inFigure 1. When the gun A is filled inA this manner it is a completeassembled unit and can be carried from place to place by the operator.The constant pressure on the grease in the chamber I6 eliminates alltrouble from air pockets and no air hose is necessary connected with thegun A. Thus the operator may use this low air pressure hand grease gunin a very efficient manner for lubricating wheel bearings of anautomobile, universal joints, water pumps, steering gear housings, etc.,with an ease that is not obtainable with other types of grease guns.Further, the gun A may be used without danger of over-greasing parts ordamaging other parts Where too much pressure is undesirable. Theoperation of the gun is simple and effective. After the gun is loadedwith grease and air the'operator simply presses the tip of the nozzle 38into the opening such as 39, which is to be greased, theV pressure ofinserting the tip sa into the opening 39 sliding the plunger 4|' intoopen position as illustrated in Figure 2, whereupon, the pressureagainst the grease in' the chamber I6 forces the grease by the checkvalve 33 around the valve 43 through the openings 45, 46 and 41 and intothe opening 39. The moment the slight pressure, which is necessary toyhold the gun A to the opening 39. iS released, the plunger 4Iautomatically closes aided by the r`spring and the pressure back of theValve 43, whereupon the grease instantly is shut off from 'beingdischarged out of the tip 38. The pressure in the chamber I4 is suicientto eject the grease from the chamber I6.

The ball check 33 prevents any back pressure land also acts as a checkvalve to maintain the grease in the chamber 30' while the plunger 4I ispushed toward the valve 33, causing grease in the lchamber 30 to beejected out of the passageways 46 and 4'I and out of the tip 38. Withthis operation the operator may increase the pressure of ejecting greasefrom the nozzle tip should the occasion arise. With the ball check 33 inthe nozzle C the operation of the ejecting plunger 4I provides a meansof instantly setting up a pressure in the chamber 30 by the sliding ofthe plunger 4I into open position which tends to close the valve 33against the pressure from the chamber I4, thus momentarily counteractingthe pressure from the chamber I4 in the pushing of the tip 38 intolubricating position.

The angular position of the nozzle C in relation to the cylindrical bodyand handle portion Il] of the gun A is of importance in permitting theoperator to more easily place the tip 38 to the opening to belubricated. The sleeve of the nozzle Cv is fixed in this angularposition, thus holding the same rigid so that the tip 38 may be operatedto open the nozzle C.

The unitary nature of the nozzle C with its tapered formation permitsthe check valve to be easily removed and the washer 43 readily replacedby removing the screw 44. The check valve` nozzle construction isvirtually in a onepiece housing, eliminating -packing joints and givinga rigid end to the gun. The grease is forced mainly by air pressurebeyond the check valve to provide an ecient low pressure grease gun. Thecombination check valve with the slidable ejecting nozzle constructioninsures perfect operation in the ejecting of the grease quickly andeasilyinto the opening to be lubricated. The floating piston assembly Bis balanced by the bearing flanges projecting from either side of thesame, thus permitting the piston to run freely in the cylinder.

In accordance with the patent statutes I have set forth the principlesof my grease gun and I desire to have it understood that the inventionshould be interpreted to the broadest scope of the following claims withsuch obvious structure as may come within the same.

I claim:

1. A hand air pressure grease gun including an air chamber, a greasechamber, a floating piston assembly between said chambers, a dischargenozzle including a check valve and movable closure plunger valveinjecting tip having a valve head including a flexible removable sealthereon to seal said nozzle in one position, and spring means urgingsaid nozzle into closed position.

2. A hand operated air pressure grease gun including, a hollow body, anair chamber in said body for compressed air, a grease chamber in saidbody, a oating piston separating said 75 accento chambers', and anangularly disposed nozzle connected to said grease chamber, normallyclosed by a valve closed by grease pressure, said nozzle including avalve and means for automatically ejecting grease when opened bypressing the nozzle against the bearing to be lubricated.

3. A oating piston assembly for cylinders of grease guns including, apair of oppositely disposed leather cups, bearing member engageable withthe inner surface of the cylinder spaced outwardly from the free edgesof each of said cups, and means for holding said assembly together,whereby the same may be iioated in a cylinder to operate freely ineither direction.

4. A piston assembly for grease guns including, packing means, andbearing means on either 'side of said packing means engageable with theinner wall of the grease gun to support said piston assembly freelyslidable in a floating nature to operate in either direction guided bysaid bearing means against getting out of operative alignment.

5. A floating piston assembly for grease guns and the like adapted to beoperated in either direction including, packing means engageable againsta cylinder wall, bearing means on either side of said packing means andspaced therefrom engageable against the cylinder wall, and means forclamping the elements of said piston assembly together.

6. A hand operated grease gun for 10W pressure greasing including, acylindrical hollow handle member closed at one end, a floating pistonassembly freely slidable in either direction in said handle member, anoffset tapered nozzle on the other end of said handle, a check valve insaid nozzle, and a slidable release valve plunger ejecting tip having ailexible removable valve head thereon against which grease operates11n-y der pressure for normally closing said nozzle and which may beoperated for opening the same by pressure on said tip.

7. A grease ejecting nozzle for grease guns comprising, a tapered tubeadapted to be xed to the grease gun, a ball check valve, longitudinalribs adapted to guide said valve, a` removable collar seat'l for saidvalve, shoulders co-operating with said ribs to limit the movement ofsaid valve in a direction away from said collar seat, a slidable plungervalve ejecting tip in the apex of said tapered tube, a valve head onsaid plunger valve, a seat in said tube cooperable with said valve head,and spring means for holding said slidable plunger valve ejecting tipnormally in closed position.

8. A grease ejector nozzle for grease guns including, a tapered bodyportion, a removable check valve, a grease ejecting tubular plunger inthe apex of said body portion slidably positioned in said nozzle, avalve shoulder and guide for said plunger, a valve member carried on theend of said plunger, screw means for holding said valve shoulder to saidplunger, spring means for normally closing said valve of said plungeragainst said valve shoulder, and an ejecting tip secured to saidplunger.

9. A hand operated air pressure grease gun including, a hollow body, anair chamber for compressed air in said body, a grease chamber in saidbody, a floating piston separating said chambers, a nozzle on saidgrease chamber nor-

